Recently, in the United Kingdom, the use of wax, especially mineral hydrocarbon wax, in gum bases, has come under scrutiny. There is a perception in the United Kingdom that it may not be desirable to use wax in gum bases. This perception could result in possible regulatory issues, in the United Kingdom, concerning the use of wax in gum base.
Unfortunately, one cannot merely remove wax from a gum base without possibly compromising certain desirable characteristics of the resulting chewing gum product. Wax provides a number of functions in the gum base. For example, wax can influence the release of flavor from the gum product. Furthermore, wax aids in the curing of the finished gum product that is made from the gum base. Additionally, wax contributes to the shelf-life of the finished gum and its texture.
Although some gum bases are known that do not contain wax, they, the inventors believe, typically do not have the chew characteristics, in addition to other characteristics, of typical chewing gums that are created from wax containing gum bases. Heretofore, gum bases without wax were not created in response to any regulatory concerns, but rather, were merely created as part of bases to achieve other ends, for example, a non-tack gum. Therefore, in certain instances, compromises with respect to certain characteristics may have been made to achieve other results, e.g., non-tack, reduced calories, etc.
U.S. Pat. No. 3,984,574, issued to Comollo, discloses an adhesive chewing gum base in which the non-tack properties were achieved by eliminating conventional chewing gum base ingredients which were found to contribute to chewing gum tackiness, and by substituting non-tacky ingredients in place of the conventional ingredients. Specifically, it was discovered that three classes of materials account for conventional chewing gum tackiness. These materials are elastomers, resins, and waxes.
Comollo eliminated natural and some synthetic elastomer from the chewing gum base, and substituted in their place one or more non-tacky synthetic elastomers such as polyisobutylene, polyisoprene, isobutylene-isoprene copolymer and butadiene-styrene copolymer. Comollo also eliminated the tack-producing natural resins and modified natural resins and used instead relatively high amounts of hydrogenated or partially hydrogenated vegetable oils or animal fats. Finally, Comollo completely excluded waxes from the gum base, but included polyvinyl acetate, fatty acids, and mono and diglycerides of fatty acids.
There is therefore a need for a method for removing wax from gum bases without compromising the characteristics of the resultant gum. Likewise, there is a need for a gum base not having wax, but exhibiting the characteristics of gum bases that do include wax.
In constructing bubble gum bases, typically, such bases contain elastomers, elastomer plasticizers, fillers, softeners, waxes, and other optional ingredients such as colorants and antioxidants. Softeners typically used in gum base include hydrogenated vegetable oils, fatty acid esters, acetylated fatty acid esters, acetylated fatty acid esters, glycerol triacetate, and the like. Generally, glycerol triacetate and acetylated fatty acid esters such as acetylated mono-, di-, and tri-glycerides are used to soften vinyl polymers, in particular, polyvinyl acetate.
It has been found that in at least some experimental wax-free gum bases that were constructed that blocking (agglomeration of pelletized base while stored in a package) occurred. To prevent blocking, shipping and storage of the product in refrigerated areas was suggested. It was believed that a temperature of around 10.degree. to 12.degree. C. would prevent such blocking.
However, even under such conditions, certain gum bases still agglomerate. Rheological glass transition (Tg) temperatures (the temperature at which cold-flow or,deformation may begin to occur) of certain gum bases indicated that shipping and storage temperatures of at least 6.degree. to 10.degree. C. would be required, instead of 10.degree. to 12.degree. C., to prevent blocking. Such shipping and storage temperatures are not cost effective. In fact, such temperatures may not be possible when shipping in, or to, certain locations.
There is therefore a need for improved wax-free chewing gum bases.